Method of electroplating and apparatus therefor



Jan. 26 1926. 1,570,819

, B- BART I METHOD OF ELECTROPLATING AND APPARA TUS -'X HEREFOR FiledOct. 11 1923 2 'Sheeti-sneet 1 INVENTOR Elas Lus Bari o/ii w ATTORNEYJan. 26 1926. 1 1,570,819

' B. BART METHOD OF ELECTROPLATING AND APPARATUS wna'nn'ron Filed Oct.11 1923 2 Sheets-Sheet 2 INVENTOR BZaszusBa/rt Patented Jan. 26, 1926.

UNITED STATES 1,570,819 PATENT OFFICE.

BLASIUS BART, OF EAST ORANGE, NEW J EBSEY.

METHOD OF ELECTROPLATING AND APPARATUS THEREFOR.

Application filed October 11, 1923. Serial No. 667,797.

To all whom it mag concern: Be it known that I, BnAsrUs BART, a citizenof the United States, and resident of East Orange, in the county ofEssex and State of New Jersey, have invented certain new and usefulImprovements in Methods of Electroplating and Apparatus Therefor, ofwhich the following is a specification.

The invention relates in general to an improved method for treatingforms, such as molds and articles of commerce to a deposit or coatingformed thereon by an electrolyt c action while suspended in theelectrolytlc bath and which method will be referred to hereinaftergenerically as an electroplating operation and the invention alsorelates to an improved form of mechanism constituting part of anelectrolytic apparatus.

In the art of electrolytic deposition it is a usual practice to suspenda plurality of the forms or articles to be coated in a suitable tank,and to pass electric current from a series of anodes to a series ofcathode plates positioned in this tank. In actual practice, however, itis found that the electrostatic conditions in certain parts of the tankare diiferent and accordingly certain of the objects under treatment aremore heavily and more rapidly coated than are those objects which aredisposed in a part of the electric field where the electrical conditionsare not so favorable to the desired rapid and efficientelectro-depositing or electroplating rocess. The necessity of Watchingthe different articles while under treatment adds materially to thelabor cost; requires the construction of a tank which permits readyaccess to the articles along the entire "length of the same and evenwith the exercise of extreme care there is no assurance that all ofsimilar articles in the tank will be uniformly treated or coated.Accordingly, the primary object of the invention is to provide for thehandling of the articles in such way that all of the articles will havedeposits of equal depth thereon or will be-uniformly coated irrespectiveof variations in depositing activity at different portions of the bath,and in which it will be'necessary simply to position the articles intothe tank at one end thereof and remove the finished articles at the sameor another point in the tank aftereach article has been subjected to atreat ment for a prefixed and predetermined time while in the bath. I

Broadly, I attain this hase of the invention by causing all 0 thearticles to traverse the same path while positioned in the tank andinthis way assure a uniformity of treatment of all of-the articles andthe subjection of each article to all of the varying electricalconditions which may happen to be present in the tank.

It has also been found in practicing the art of electrolytic depositionthat the side or projecting portion of the article closest to the anodelate becomes more thickly and more rapi 1y coated than the side facingin the opposite direction or more remote from the adjacent anode plate.Further it has been found that the electrolyte which is immediatelyadjacent the depositing coating becomes impoverished and the resultingplating operation becomes irregular, presumably due to the irregularityin the movement of the depositing salts from the richer to theimpoverished portions of the electrolyte.

Another object of the invention incidental to the desideratum to providea uniform deposit on all portions of the article under treatment, is. toprovide for the handling of the articles while in the bath in suc way aswill present all portions to be coated to the anode plate or plates insome period during the plating operation, and incidentally to insure themaintenance of rich and uniform electrolyte at all times adjacent theelectrolytic depositing surface.

Broadly, I attain this phase of the invention simply by rotating thearticle while 'it is being advanced bodily through the differentelectrical parts of the bath. The effect of this rotary movement is topresent all ortions of the object repeatedly to each ano e plate duringthe cycles of movement of the article imder treatment and incidentallyto maintain the electrolyte in a:

stirred or gently agitated condition.

Referring to the physical aspect of the disclosure the primary object 0tion is to provide a simple construction .the invenwhich can be actuatedeconomically to,

maintain the article under treatment in.

proper operative relation to the cathode and anode plates in the bath,and to cause the articles'to move through thebath with a certaininterval of lapsed time to insure the requisite thickness of coatingwhen the articles have traversed a given bath, and to maintain thearticles rotating or other wise moving to present different portions tothe electrolyte plates and to prevent stagnation of the surroundingelectrolyte.

The invention features the positioning of a plurality of carriages on anendless track, positioned above the tank which carriages are driven bysome suitable mechanism, such as an endless chain drive, and eachcarriage is provided with means for facilitating the quick mounting ofthe articles thereon and the similar demounting of the finished articlesas they pass the operator and without interrupting the continuity ofdrive of the articles in the bath.

It is understood that the electric current used in the electroplatingoperation is low in voltage but extremely high in amperage. and as anexample of one such current it may be noted that in one practicaloperation of the invention herein disclosed a current of one volt andfrom one hundred to two hundred amperes were used.

With such high amperage extreme care must be exercised in order tominimize any resistance to the passage of current to the article undertreatment. It not infrequently happens that bad connections acrosshinged parts for instance cause the parts to become red hot.Accordingly, another object of the invention is to provide a form oftravelling carriage for supporting the articles as they are movedthrough the bath and which carriage will feature the minimizing ofresistance to the passage of electric current therethrough to thesupported articles.

Featuring the general desideratum for simplicity of construction andeconomy in operation another object of the invention is to provide asimplified means for furnishing rotary movement to the suspendedarticles as an incident to the movement of the carriage along thetracks.

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying drawin s and in part willbe more fully set forth 1n the following particular description of oneform of mechanism embodying my invention, and the invention alsoconsists in certain new and novel features of construction andcombination of parts hereinafter set forth and claimed.

In the accompanying drawings 0 Figure 1 is a transverse sectional vlewtaken on the line 1- 1 of Figure 2 showing a portion of an electrolytictank of conventional form with one of a series of article supportingcarriages shown in end elevation and constituting a preferred embodimentof Z ne of the physical features'of the invene 10D 1 Figure 2 is a viewin side elevation of the structure shown in Figure 1 looking at the samein the direction of the arrow numbered 2; and.

plan view looking down Figure 3 is a to he arrow numbered 3 in asindicated by t Figure 1.

In the drawings there is shown in diagrammatic outline one side of anelectrolytic tank 10 of conventional construction and which tanks areusually from fifty toa hundred feet in length and eight or ten feetwide. The tank contains a sultable anode a in an electrolyte 11.electrolyte in the tank is an endless track, a portion at one side ofthe tank being shown at 12. This track is a copper bar operativelyconnected to an electric current generator and hereinafter referred toas a source of electric energy. The upper face ofthe track is providedwith a concaved groove 13 and one side of the track, such for instance,as the inner side 14.- is vertically disposed to form a side contactingface. Positioned above the track is a source of power herein shown to bean endless chain 15 o eratively Positioned above the connected with gearwheels (not s own) at opposite ends thereof for driving the chainparallel with and in a plane above the track. Positioned along thelength of the chain are a. plurality of carriages one of which 16 isillustrated. The carriage includes, in effect, a longitudinallyextending frame 17 provided on its underside with a pair of supportingrollers 18 and 19, journalled therein respectively on shafts 20 and 21for supporting the carriage from the track. The periphery of the rollersare convex in axial cross-section so that the rollers will conform toand fit in the concavity of the grooved upper face of the track andprovide a relatively extensive contact between the track and therollers, as shown in Figure 1. The carriage includes an offset bracket22 somewhat U-shape as shown particularly in Figure 1 and extendingtransversely of the frame 17 and projecting'laterally beyond the sideface 14 of the track. A vertically disposed shaft 23 is journalled inthe bracket and is free to slide therein for a limited vverticalmovement. A friction disk 24 having a concaved groove 25 on its underface and concentrically disposed with reference to the shaft, is securedto'the shaft adjacent the upper end thereof. The groove 25 is designedto fit and frictionally engage the top of the roller 19 to provide afriction gear between one of the rollers engaging the track and thedepending shaft.

It will be seen from this construction thatthe movement of the carriagealong the tracks will cause the roller 19 to rotate the friction diskresting on the same and thus cause the shaft 23 to rotate about itsvertical axis. At the same time the rollers are intended to maintain apolished contact with the upper grooved face of the track and likewiseto maintain a similar contact respectively on pins 28 and 29 carried ban extension 30 formed at the lower end 0 the bracket 22. It is obviousthat these rollers maintain a rolling contact with the side face 14ofthe track and tend to minimize any tendency of the carriage toswinglaterally of the track. Inv order to further insure the passage ofthe electric current to the shaft and thus avoid any resistance whichmay develop at the hearings of the several ro lers, a sliding contactbrush 31 is carried by the extension 30 and bears resiliently on theside face 14 of the track.

It is necessary in the practical operation of the device of thecharacter under discussion, to provide some means for quicklypositioning the articles in place as the carriage moves past theoperator, and for this urpose the lower end of the shaft is providedwith a bifurcated head 32 through which is extended a hook pin 33,designed to be engaged by a hook 34. This hook may be formed directly onthe article to be electroplated and which article is shown symbolicallyat 35. It is a usual practice to position the articles to be coated in asuitable carrier and the reference character 35 may symbolicallyrepresent such a carrier of the article as well as the article itself.For the purpose of holding the. hook in place against accidentaldisplacement and further for the purpose of 'maintaining the electricpath between the shaft and the article, a spring contact brush 36 hasone end secured to the head 32 and bears ticle 34. From thisconstruction it is seen that current isconducted through the brushacross the hinge connection provided by the hook and pin and here againevery effort is made to minimize resistance to the passage of theelectric current.

In operation and assuming that the tank is filled with the desiredelectrolyte and that the anode and cathode plates are in position andthe device otherwise in usual 0 erative position, the operator willplace tiie articles to receive the deposition, one after another on thesucceeding carriages as they pass his station at one end or othersuitable point of the tank. The travel of the chain drive is soregulated that the articles receive their desired thickness ofdeposition when they have describedone, or any other desired multiple ofcycles of movement through the tank. The movement of each articlethrough all portions of the tank will on the arinsure a uniformtreatment of all of the articles irrespective of the difference in thedepositing or other plating activity at different portions of the pathof movement. As the articles are rotated about the axis of thesupporting shaft it will result that all portions of the article arebrought into position facing the anode at each cycle of movement. of thearticle and the speed of rotation is so regulated that the differentsides of the article are repeatedly presented to each anode plate as thearticles are moved across the face of the plate.

By practicing the method herein suggested it is possible to obtain auniform coating or deposit'on all similar articles which have passedthrough the apparatus. Further, there is a saving in labor cost forthere is no necessity of inspection by the operator at difierentportions of the tank and one 35 operator at one end of the tank caneasily demount a finished article and-promptly replace it with a fresharticle to be treated. Considering the structural features of thedisclosure this uniformityin coating is attained with economy both inthe amount of electrolyte used, in the anode consumption and in thecurrent consumption. Incidentally there is also featured the practicalelimination of heatingefiects with resulting saving in wear on t eequipment. There has been eliminated any necessity of lifting bulkyapparatus and the operation is contmuous.

.Having thus described my invention, I claim:

1.'In the art of electrolytic deposition where a series of anodes areused and where the depositin operation is of different activity in dierent parts of the bath, the

method which consists in causing the article to be coated to traversecontinuously a path through the several parts of the bath where thedepositing activity is variable,

subjecting the article to the electrolytic depositing action of the bathfor a prescribed period of time and causing the article durmg itspassage to present all sides thereof repeatedly to the different anodes.

2 In the art of depositing a metal electrolytlcally on a plurality ofsimilar articles 1n an electroplating apparatus where the currentstrength is apt to vary in different parts of the bath, the step whichincludes the moving of all of the articles simultaneously with the samespeed for equal intervals of lapsed time and in the same direction overan endless path through "the fields of different current strengths whilesubjecting the articles to the electrolytic depositing action of thebath whereby each article is subjected substantially to the same platingoperation.

3. In the art of coating articles by elccconsists in ositioning thearticle to be coated in'an e ectrolytic bath where the paths between theanodes and cathodes are of different electrolytic strength, and movingthe articles bodily across said paths of different strengths and along aclosed, nnn-llncar path while subjecting thearticle to the elec trolyticdepositing action of the bath and to a rotary movement about a contained3X13. 4. In the art of coating articles by electrolytic precipitation,the method which consists in positioning the article to be coated in anelectrolytic bath where the paths between the anodes and cathodes are ofdif ferent electrolytic strength, and movin the article horizontallyacross said paths 0 different strengths while restrained from verticalmovement and subjected to the electrolytic depositing. action of thebath.

5. In the art of coating articles by electrolytic precipitation, themethod which consists in moving an article bodily through theelectrolyte while subjecting the article to a rotary as well as to alongitudinal movement along a closed, endless path.

6. In the art of electrolytic deposition, the method which consists incausing the article to receive the deposit to travel through theelectrolyte over a cylindrical path while presenting difi'erent parts ofthe article to the anodes.

ticle through the electrolytic bath while subjecting the article to theelectrolytic depositing action of the bath and incidentally causing'themoving article to generate a poptinually moving current in the electroye. g c

' 9. In the art of electrolytic deposition, the method which includesthe step of advancing the article to be plated over a closed path whilein the electrolytic bath thereby to stir the electrolyte and cause it tomove continuously in a closed path.

10. In a device of the class described, the combination of a track, acarriage including a frame extending lengthwise and above the track,means for advancing the carriage along the track, a pair oflongitudinally spaced rollers riding on top of the track and supportingsaid frame and throu h the frame supporting the remainder of t ecarriage, said carriage including a bracket extending transversely ofthe frame and having a portion otfset laterally from the track,

of its weight on one of the rollers engaging the top of the track.

11. In a device of the class described, the combination of an endlesstrack, a carriage provided with rollers for supporting the same on thetrack, an endless chain operatively connected to the carria e to movethe same along the track, a vertlcally disposed shaft journalled in thecarriage and r0- vided with means for suspending artlcles therefrom, adriven disk fixed .to the shaft and resting on one of the rollers toprovide a friction gear drive between the track and the shaft.

12. In a device of the class described, the combination of an endlesstrack, a'carria e provided with rollers for supporting t e same on thetrack, an endless chain opera- .tively connected to the carriage to movethe same along the track, a vertically disposed shaft journalled in thecarriage and rovided with means for suspending art cles therefrom and afriction gear drive connection between one of the rollers and saidshaft.

13. In a deviceof the class described, the combination of anelectrolytic tank, a support constituting a source of electric energypositioned above the liquid level in the'tank, a bracket suspended fromthe support, a vertically extending shaft journalled in the "bracket andprovided with means for suspending articles in the liquid in the tank,said shaft being connected electrically to the support and adapted toconvey electric energy therethrough to the supported article and meansoperatively connected to the shaft for rotating the articles in thebath.

14. In a device of the class described, the

combination of an electrolytic tank, means for supporting in said tank aplurality of articles to be coated, means for subjecting the articles tothe electrolytic depositing action' of said bath and means'operativelyconnected to said supporting means for rotating the articles each abouta contained vertical axis.

15. In a device of the class described, the combination of anelectrolytic tank, means for supporting in said tank a plurality ofarticles to be coated, means for subjecting the articles to anelectroplating operation and means operatively connected to saidsupporting means for bodily moving all of the articles continuously overa closed path while so subjected.

16. In a device of the class described, the combination of a trackconstituting an electric conductor, a carriage provided w th a rollerrunning on said track, a shaft 1on1- nalled in said carriage andoperatively connected to the roller to be rotated thereby and ower meansengaging the carriage for moving the same along the track, said rollerand shaft constituting part of an electric circuit for transmittingelectric energy from the track through the rotating shaft.

17. In a device of the class described, the

combination of a track having a grooved.

top face, a carriage movable along the track and rovided with a rollerwith a contacting ace fitted to the groove in the top face of the track,a driven disk mounted for rotary movement in the carriage and providedwith a concentric groove fitting the contacting face of the roller and asupporting shaft journalled in the carriage and driven by said disk.

18. In a device of the class described, the combination of a trackconstituting a source of electric energy and having an exposed top andside face, a carriage movable along the track, a vertically disposedshaft provided with a rolling physical and electric contact with theside face whereby electric energy is transferred from the charged track9 directly to the shaft, a rolling contact between the top faceofthe'track and the shaft to cause the shaft to rotate as the carriage ismoved along for advancing the carriage along the' track.

19. In a device of the class described, the combination of a trackconstituting a source of electric ener y, a carriage,"power means foradvancing t e carriage along the track, means for supporting an articlefrom the carriage, a driving connection between the track and saidsupporting means for causing the supported article to rotate, saiddriving 7 connection and supporting means constituting an electriccircuit. for transmitting electric energy from the track to, thesupported article.

20. In a device of the class described, the combination of an endlesstrack, a carriage movable on the track, an endless driving memberoperatively connected to the carriage to draw the same along the track,and a verticallydisposed shaft provided with means for supportingarticles below the track, said shaft journalled in the carriage, movablebodily therewith and operatively connected to be rotated by the movementof the carriage along the track.

21. In a device of the class described, the combination of an endlesstrack, a carriage movable on the track, means for propelling thecarriage, means for supporting an article from the carriage andmechanism conthe track and means trolled by the movement of the carriagealong said trackfor causing said supporting means to have movementrelative to the carriage.

22. In a device of the class described, the

combination of an endless track, a carriage movable on the track, meansfor propelling the carriage, means for supporting an article from thecarriage and mechamsm controlled by. the movement of the carriage alongsaid track for causing said supporting means to have movement relativeto the {carriage and means for guiding the carriage along the track.

23. In a device of the class described, the combination of a trackhaving exposed upper and side contact faces, a 'carria means for movingthe carriage along t 0 track, means for supporting an article-from thecarriage and means for providingelec tric contact between saidsupporting means and both faces of the track.

24. In a device of the class described, the combination of a trackhaving exposed upper and side faces, a carriage, a plurality ofrollers'sup orting the carriage on the track, a plura 'ty of rollersengaging the. sideface of the track, means for advancing the carriagealong the track and means for removably supporting the articles from thev carriage. a

25. In a device of the-class described, the combination of a trackconstituting a. source of electric energy, a carriage, means for movingthe carnage along said track, and metallic means for supporting anarticle from the carriage and for conveying electric energy from thetrack to the supported article. I

26..A11 electrolyte apparatus including a tank; a track above the tank,a carriage movable on the track, means for suspending articles from thecarriage, means engaging thecarriage for causing the same to move thearticles through the bath in the tank, and means for conveying electricenergy to the carriage and therethrough to the article supported by themovin carriage.

27. A carriage adapte to be positioned on a track for use in supportinarticles from the track in an electrolytic ath said carriage comprisingsupporting rollers adapted to engage the track, a vertically disposedshaft", means for rotating the shaft and said shaft rovided with easilymanipulated means or securing the articles to the shaft while rotating.

28. In a device of the class described, the combination of anelectrolytic tank, means for supporting articles to be electroplated insaid tank, said supporting means being of an electric conductingmaterial, and operatively connected to a source of electric energy toconvey the energy to the supported articles, said supporting means incuding articles, said supporting means including portions which areliable tointerpose resistance to the passage of the electric energyandbrushes bridging said portions and adapted to insure the passage ofenergy to the article without material resistance.

29. In a device of the class described, the combination of anelectrolytic tank, means for supporting articles to be electroplated insaid tank, said supporting means being of an electric conductingmaterialand operatively connected to a source of electric energy toconvey the energy to the supported a hinged connection and a brushelectrica 1y connecting the parts across the hinge connection.

30. In a device of the class described, the combination of a carriage, ashaft journalled in the carriage, power means for moving the carriageand for rotating the shaft, means for hingedly connecting articles tosaid shaft and an electric brush connecting the shaft electrically withthe supported article across said hinge connecting means.

31. In a device of the class described, the combination of a trackhaving an exposed side and constituting a source of electric energy, acarriage provided with means for supporting articles therefrom andadapted to conduct electric current to the article, said carnagesupported from the track, a brush movable with the carriage andproviding a sliding electric contactbetween the carriage and the exposedside of the trac 32. 1n a device of the class described, the combinationwith a track constituting 9.

source of electric energy, and having an porting rollers, a verticallydisposed shaft,

means for rotatin the shaft and said shaft provided with easilymanipulated means for securing the articles to the shaft while rotating,said shaft provided adacent its lower end with a pin adapted to eengaged by a hook and said shaft provided with a spring adapted tosecure the hook in place on 'the pin.

341. A carriage for use in supporting articles in an electrolytic bathcomprising sufiporting rollers, a vertically disposed sha means forrotatin the shaft and said shaft provided with easily manipulated meansfor securing the articles to the shaft while rotating, said shaftprovided adjacent its low er end with apin adapted to be engaged: by ahook and said shalt provided with a spring adapted to secure the hook inplace on the pin and constituting a brush for conducting electriccurrent from the shaft to the hook.

Signed at New York city in the county of New York and State of New Yorkthis 22nd day of September, A. D. 1923.

BLA'SIUS BART.

